One thing is abundantly clear: neither political party will emerge from the 2016 nomination battle looking anything like it did when it began the marathon race. Fundamental changes are now inevitable in both political parties  and they will be irreversible.

These changes will not be so much in how the ethnic or geographic constituencies divide themselves between the parties as it will be in the policies, programs and priorities of each party.

Whether Donald Trump or Ted Cruz wins, the Republican Party will not be the same. The party of Jeb Bush, John Kasich, Chris Christie, John Boehner and Mitch McConnell has been vanquished.

And even if Bernie Sanders loses to Hillary Clinton, his ability to galvanize a new movement and to win young people  of all races  in the Northeast and Midwest presages a new Democratic Party.

To understand what is happening, look back to the ’60s.

Before Barry Goldwater won the nomination in 1964, the Republican Party was a liberal but paler imitation of the Democrats. Largely centered in New York and the Northeast, it was a Republican governor, Nelson Rockefeller, who was the first to legalize abortion, and a Republican jurist, Harry Blackmun, who wrote the majority opinion in Roe v. Wade.

But 1964 changed the GOP irrevocably. Its power base shifted to the Sun Belt and its dominant constituency became small business and religious voters. The party of Thomas Dewey and Rockefeller died in 1964.

Before 1968, the Democratic Party was more hawkish than the GOP. Its largely internationalist positioning was in contrast to the isolationism of Republicans. It opposed civil rights and catered to its Southern base. It embraced fiscal orthodoxy and rejected social change.

After 1968, it became the anti-war party and embraced civil rights, feminism, environmentalism, gay rights, rights for the disabled and a host of social causes.

2016 will be a year of changes of similar magnitude in each party.

The Democrats will jolt permanently to the left. Socialized medicine, much higher taxes on the wealthy, opposition to fracking, a fanatical fight against climate change, harsh anti-Wall Street measures and ever more radical social change will be its hallmarks. Prison reform and a fundamental change in the criminal justice system will move to center stage. These changes will leave the likes of the Clintons and even Barack Obama far behind.

The Republicans will harden their anti-immigration position, will turn away from the party’s historic commitment to free trade and will join the Democratic left in regulating Wall Street and cracking down on the Federal Reserve. They will embrace privacy policies and impose them on the National Security Agency and the intelligence community. The Bushes and Mitt Romney will be left far behind.

We cannot even begin to predict where these changes will lead, any more than we could have known that gay rights would rise in the Democratic agenda or abortion opposition in that of Republicans. Neither issue was on the radar screen as the changes were happening in each party in the ’60s.

These changes, in each party, reflect massive outrage at the irrelevance of our government and its politics. In the 1960s, the gap between Eisenhower’s Republicans and Kennedy’s Democrats was minuscule. The Goldwater and Eugene McCarthy/George McGovern/Robert F. Kennedy candidacies drove the parties further apart. Real choices emerged. Fundamental assumptions became debatable. A genuine left and right came to be.

So now we are going to widen the ideological divide still further. The Trump/Cruz Republicans will clash with the increasingly Sanders-esque Democrats, and more topics and fundamental questions will come into play.

Democracy will no longer be about minor differences on how to cut the deficit or incremental approaches to waging war abroad. Huge fissures will open, and everything will be in play. The people are taking back their parties and insisting that they become vehicles for big changes in a system that all agree is failing.